Chair



Nov. 2s, 1944.. A R, BOERNER 2,363,935

CHAIR vFiled Feb. 3, 1941 3 Sheets-Sheet 1 f-Lwwwc ATTORNEY.

Nov. 1944,

CHAIR Filed Feb. 3, 1941 A. R. BOERNER" 5 Sheets-Sheet 2v INVENTOR. ,swr/vw? 1P. afm/ff ATTORNEY.

Nov. 28, 1944.

A. R. BOERNER 2,363,935

CHAIR' Filed Feb. s, 1941 s sheets-sheet s INV ENTOR. HPI/i0@ A. BOER/VEA.

ATTORNE Y.

Patented Nov. 2s, 1944' 2,363,935 CHAIR Arthur R. Boerner, Milwaukee, Wis., assignor, by

mesne assignments, to Automatic Products Company, Milwaukee, Wis., a corporation of Wisconsin Application February 3, 1941, Serial No. 377,084

(Cl. 155-77) j 7 Claims.

This invention relates to an improvement in chairs of the type having a tiltable seat.

Oflice chairs with a tilting seat and back have long been known and widely used, and, as commonly constructed, comprise essentiallya base, a vertically adjustable spindle supported on the base and projecting upwardly therefrom, a headpiece iixed to the upper end of the spindle, a spider secured to the underside of the seat of the chair and pivotally supported on the head-piece, and means for resiliently resisting tilting movement of the seat and spider about thel pivotal mounting of the spider on the head-piece. In this priorconstructions the pivotal support of the spider on the head-piece is usually at or near the vertical axis ofthe spindle, and the means which has been employed for resiliently resisting the tilting movement of the seat` about its pivot has usually comprised either a spring or rubber block as a resilient source of power, an adjustable abutment on or connected to the head-piece and against which one end of the spring or rubber block bears, and an arm or similar means fixed to the seat or spider and cooperable with the opposite end of the spring or rubber block from that seated against the abutment. With such a construction the forward end of the seat, when it is tilted rearwardly, rises to a degree as great or greater than that to which the rearward end of the seat moves downwardly. Moreover, the arm carried by the seat or spider, which applies pressure or transmits motion to the spring or rubber block, acts through a relatively short lever arm and consequently the spring or block may be.

made of reasonable size.v

The present invention proposes to constitute the head-piece of such a chair with an extension which projects forwardly from the head-piece to a point adjacent the front of the seat. The spider is pivotally connected to the forward end of this seat at a point near the front of the seat so that when the chair seat is tilted rearwardly the upward motion of the forward end thereof is min-v imized thereby allowing the user of the chair to lean backwardly to a degree suitable to his comfort or inclinations without raising his feet ofi the door. This advantage introduces into the structure another problem rising out of the fact that the portion of the underside of the seat orV of the spider available for transmitting pressure or motion to the spring or rubber block must act through a relatively long lever arm, and hence the force that must be supplied to resiliently op pose the rearward tilting of the seat would appear to require an unduly heavy, large spring or rubber cushion. The present invention, however, makes it practical to provide a light weight spring or rubber block of appropriate size as a source of force and utilizes the light force available to such mechanical advantage :as to supply the power necessary to effectively yieldably resist the rearward tilting of the chair seat. This action is had by multiplying the force with mechanical means which may be gearing, but preferably is a compound lever mechanism which is interposed between the spring or rubber block and the spiderof the chair seat. By virtue of this arrangement it is practical not only to employ a spring or rubber cushion of appropriate lightness and size, but also the adjustment available is much more easily made, and much more iine and precise.

Another object of the invention is to provide a chair of this character wherein the tiltable mounting of the chair, seat, and back are so coni stituted and so closely and advantageously organized as to simplify and compact the construction while maintaining it strong and rugged and stable, and rendering its action smooth and comfortable.

Other objects and advantages reside in certain novel features of the construction, arrangement, and combination of parts, which will be hereinafter more fully described and particularly pointed out in the appended claims, reference being had to the accompanying drawings forming a part of this specication, and in which:

Figure l is a view on a reduced! scale showing generally a chair constructed 'in accordance with the present invention;

Figure 2 is a fragmentary view in longitudinal, vertical cross section taken on line 2-2 of Figure 3 and looking in the direction of the arrows,

and with parts shown in elevation for the sake of simplicity in illustration;

Figure 3 is a View in horizontal cross section taken on line 3-3 of Figure 2 and looking in the direction of the arrows; A y

Figure 4. is a fragmentary view partly in side elevation and partly in vertical section, illustrating a modication of the force-multiplying means which may be employed between the resilient element or source of force on the headpiece and the spider; and i Figure 5 is a similar view showing such a force-multiplying means in the form of gearing.

Referring to the drawings, it will be seen that a chair embodying the present invention comprises generally a base designated at B, a seat in the spider arms Il).

designated at S having side arms A fixed thereto', and a tiltable chair-back designated at T.

The base B may be of any suitable type and has the usual legs I equipped with casters or rollers 2. The legs I diverge from the hub 3 of the base. A vertical spindle 4 is supported in the hub 3 of the base in the usual manner, and is controlled as to its vertical adjustment by means of a capped nut 5 in the conventional or any suitable manner.

A head casting 8 is securely fixed to the top of the spindle 4 and has riveted thereto a U-shaped head-piece 1 of heavy gauge sheet metal, the body portion of the U-shaped head-piece resting iiatly on the head casting 6 and being riveted or otherwise rigidly fastened thereto. 'I'he legs of the U-shaped head-piece .1 extends vertically and their upper ends are riveted, welded, or otherwise suitably secured to forwardly projecting metallic supporting arms 8. These arms 8 extend well forward of the seat; that is, to a point adjacent the forward edge of the seat, and the forward ends of the arms are pivotally connected to the metallic spider arms I0, the ends of which are fastened by means of screws II tothe underside of the seat S. The pivotal connection between the supporting arms 8 and the spider arms I8 is effected .by means of a pivot pin 8 which also extends' through alined pivot openings provided therefor in the forward ends lof the supporting arms and The forward ends of the arms 8 are cross-braced preferably by means of a -cross strip I2 provided with integral down-turned ends I3 tting over the outer. surfaces of the forwarr'i ends of the arms 8 and welded thereto. The pivot pin 8 also passes through openings provided therefor in the downturned end I3 of the crossbrace I2.

Means is provided for yieldably or resiliently resisting pivotal movement of the seat S about the axis of the pivot pin 9 and comprises a tension rod I5 extended through a non-circular opening provided therefor in anabutment lug I6 Awhich may be formed integral with the body portion of the head-piece 1 and of such width'as to overlap the rearward edges of the legs thereof. The head of the tension rod lI5 abuts fiush up against this abutment lug I8, and while the shankv thereof is circular for the major portion of its extent, it does have a non-circular portion I5' adjacent the head which interiits with the noncircular opening in the lug I8 to hold the tension rod I5 against rotation. The outer end of the tension rod I5 is threaded to adapt it to be interthreaded with a hand nut I1. The inner end of the hand nut I1 abuts a spring cu-p or spring abutment I8 which is slidable along the tension rod I5 and which engages the outer end of a compression coil spring I 8. The inner end of the spring I9 engages a spring cup or abutment 20 having its rearwardI face formed with diametrically opposite notches to adapt it to fulcrum or knife edges 2|' provided on the downwardly extending arm -2I of an approximately T-shaped lever designated al a wholeat 22. The-lever 22 may conveniently be built up of sheet metal parts shaped asillustrated in the drawings and riveted together.v 'I'he forwardly extending lateral arm 424'of the lever 22 is pivoted or fulcrumed as at 23 on the upper'portions oi' the legs of the headpiece 1. The rearwardly extending lateral arm 2l of the T-shaped lever 22 is pivotally interconnected as at 25' to the lower ends of the legs of a downwardly and forwardly inclined swing-V inirmember in the form' of a U-shaped link 28,

the upper portions of the legs of this link 26 being pivotally connected by a pivot pin 21 to the spider arms III.

With the construction as thus far described, when the user of the chair tilts backwardly on the seat S, the link 26is thrust downwardly and forwardly and rocks the lever 22 about its fulcrum 23 in a counter-clockwise direction as viewed in Figure 2, thereby swinging the knife edges 2l.' of the downwardly extending arm 2| of the lever 22 forwardly. The coil spring I9 acting through the spring cup 20 resists its forward movement of the knife edges. 2|' and lever arm 2I and consequently yieldably resists the tilting of the chair seat. Due to the fact that the axis of tilt (pivot pin 9) of the chair seat is disposed well forwardly of the seat, that is near the front edge thereof, tilting movement of the chair seat is had with a minimum amount of upward movement of theV forward end of the chair seat. 'I'his enables the user of the chair to lean back as far as he may desire without swinging the forward end of the chair seat upwardly to such an extent as to lift or raise his feet ofi of thel floor. However, the

' tilting of the chair seat backwardly to an extreme or dangerous extent is prevented by the positive engagementvof the lower edges of the side flanges of the channel-shaped lever arm 25 with the lug I8 or preferably with cushions or bumpers 28 fastened to the lug I6. The cushions or bumpers 28 may be constituted of blocks of felt, rubber or the like, adhesively or otherwise suitably attached to the lug I8 of the head-piece In the modifications of the invention shown in Figures 4 and 5, the spindle 4 and head casting 8 are employed as before. A U-shaped headpiece 1 corresponding to the head-piece 1 is also provided, but in these modifications, each headpiece 1' has integral forward extensions 8' pivotally connected by a pivot pin 8 to their spider arms I0 at a point near the front edge of the seat.

In both l modifications, the spider arms are cross-connected at longitudinally spaced points by cross bars 10 and 1I, the cross bars being integral with, welded, or otherwise suitably secured to the spider arms so as to be rigid therewith. These cross bars serve as stops, the cross bar 10 engageable with the portion 12 of the head-piece to limit the rearward tilting of the seat, and the cross bar 'II engaging the bottom portion 13 of the head-piece to limit theforward tilting movement of the seat.

In the modification shown in Figure 4, a coil spring 15 provides the relatively light and elastic source of force.` 'I'his spring is vertically disposed and is interengaged at its upper end with a spring abutment 16 fulcrumed on a knife edge 11 Vprovided on the transversely extending upper portion of the head-piece. 'I'he lower endl of the spring is interiitted with an adjustable spring abutment- 18, the position of which is controlled by an adjusting screw 19 equipped with a, handwheel 88. The screw 19 is interthreaded with a threaded bearing 8i provided in one of the arms 4of a lever 82. The lever 82 is fulcrumed as at 83 lever 82 and link 84 provide an appropriate forcemultiplying means between the spring and the spider.

` In the modification shown .in Figure 5, a spring 15, spring abutments 16 and 18, adjusting screw 19, and hand wheel are employed as before.

aseaess The screw llistinterthreaded `with the bearing in `the long-f arm of` a lever; designated generally at` 85.` 4The short ann of. thislever, however, is formed `with a gear segment 86 which meshes with a lswinging memberinl the form of a rack "having its upper -endpivotally interconnected as at 88 lwith the spider arms Il). With such a constructionA `the head piece must be fashioned toprovide an appropriate guide 89against which the rack B'ljbears. There is sufficient looseness or lost motion `in the *mesh of the gear teeth between the segment and the rack to provide for the necessary movements.. In this instance the force-multiplying means takes the form of suitable gearing.

While I have shown and described several constructions in whichthe invention may be advantageously embodied, it is to be understood that the constructions shown have `been Selected merely for the purpose of illustration or example, and that various changes in the sizel shape, and arrangement of the parts may be made without departing from the spirit of the invention or the scope of the subjoined claims. Y

I claim:

1. A chair of the type having a base, a seat, and a back, and comprising a spindlesupported on the base, a head-piece fixed to the upper end of the spindle and having an extension projecting forwardly thereof to a point adjacent the front of the seat, a spider secured to the underside of the seat, a pivotal connection between the forward end of the extension and the portion of the spider located near the front end of the seat, and

means for resiliently resisting tilting movement of the seat about saidpivotal connection and comprising a tension rod having one end anchored to the rearwardly extending arm of the T-shaped lever.

2. A chair of the type having a base, a seat, and a back, and comprising a spindle supported on the base, a head-piece fixed to the upper end of the spindle and having an extension projecting forwardly thereof to a point adjacent the front of the seat, a spider secured to the underside of the seat, a pivotal connection between the forward end of the extension and the portion of the spider' located near the front end of the seat, and means for resiliently resisting tilting movement of the seat about said pivotal connection and comprising a tension rod having one end ,anchored on the head-piece, a compression spring surrounding the rod, a hand nut threaded on the rod and providing an adjustable abutment for one end of the spring, a T-shaped lever having a forwardly extending arm fulcrumed on the head-piece and having a downwardly extending arm provided and a back, and comprising a spindle supported on the base, a head-piece xed to the upper end of the spindle and having an extension projecting forwardly thereof to a point adjacent the front of the seat, a spider secured to the vunderside of the seat, a pivotal connection between the forward end of the extension and the portion of the spider located near the front end of the seat, and means for resiliently resisting tilting movement of the seat about said pivotal connection and comprising a tension rod having one end anchored on the head-piece, a compression spring surrounding the rod, a hand nut threaded on the rod and providing an adjustable abutment for one end of they spring, a T-shaped lever having a forwardly extending arm fulcrumed on the head-piece and having a downwardly extending arm cooperable with the end of the spring opposite the hand nut, said.1ever having a rearwardly and downwardly inclining arm, and a link having one end pivotally connected to the spider, said link inclining forwardly and downwardly and having its lower end pivotally connected to the rearwardly and downwardly extending arm of the T-shaped lever.

4. A chair of the type having a base, a seat,

' and a back, and a spindle supported on the base,

with a bifurcated lower end straddling the tena head-piece xed to the upper end of the spindle' and having an extension projecting forwardly thereof to a point adjacent the front of the seat, a pivotal connection between the forward end of the extension and the seat at a point 'near the front end of the seat, and means for resiliently resisting tilting movement of the seat about said pivotal connection, comprising a lever, means for pivotally mounting said lever intermediate its ends on said head-piece, abutment means at one end of said lever, opposed abutment means associated with said head-piece, a resilient compressible member disposed between said abutment means, and a swinging member having a pivotal connection with said seat and being provided at its free end with a rack portion, a segmental gear portion carried by the other end of said lever and in mesh with said rack whereby to compress said compressble member when the rear portion of the seat is depressed.

5. A chair of the type having a. base, .a seat,

and'a back, and a, spindle supported on the base, a head-piece fixed to the upper end of the spindle and having an extension projecting forwardly thereof to a point adjacent the front of the seat, a pivotal connection between the forward end of the extension and the seat at a point near the front end of the seat, and means for resiliently resisting tilting movement of the seat about said pivotal connection, comprising a lever,

means for pivotally mounting said lever inter mediate its ends on said head-piece, abutment means at one end of said lever, opposed abutment means associated with said head-piece, a

resilient compressible member disposed between said abutment means, and a swinging member having a pivotal connection with said seat and being provided 'at its free end with a rack portion, a segmental gear portion carried bythe other end of said lever and in mesh with said rack whereby to compress said compressible Y member when the rearv portion of the seat is depressed and a strap member engaging said swinging member to maintain the rack portion thereof in operative engagement with said segmental gear portion 6. In a tiltable chair, a seat, a base, a pivotal connection between said seat and said base, a

lever pivotedto said base for movement about an axis spaced from said -lpivotal connection, opposed abutment means on said lever and said base, resilient compressible means disposed between said abutments, and a link operatively connected between said seat and said lever to transfer force from said seat to said lever as said seat is tilted downwardly, the distance between the pivotal point of the lever to the base and the pivotal point between the link and the lever l0 being much less than the distance between the abutment means on the lever and the pivotal point between the lever and the base.

7. In a tiltable chair, a base, a seat, a pivotal connection between said seat and base, a lever,-

means for connecting said lever to said base for pivotal movement about a iixed axis spaced from said pivotal connection, resilient compressible means acting upon said lever to urge it to rolever whereby backward tiltingof said seat will cause said lever'to rock against the action of said resilient compressible means.

ARTHUR R. BOERNER. 

